1. Field of the Invention
The present invention relates to a computer system with a display and, more particularly, to a power and signal control device for a flat panel display used in a laptop personal computer or laptop word processor.
2. Description of the Related Art
In the field of personal computers, small, light and handy-to-carry laptop computers are replacing conventional desktop computers. This trend is true of word processors. The present laptop computers are normally equipped with flat panel display devices such as liquid crystal display devices (LCDs) or plasma display panels (PDPs). Furthermore, many of such laptop computers are connectable to external color cathode ray tubes (CRTs). This is because the flat panel displays are usually adapted to monochrome display and color CRTs are more easy to watch than the flat panel displays for applications adapted for color displays. Hence, a flat panel display and an external color CRT will not be used simultaneously.
When an external color CRT is used, a normally equipped flat panel display may be an encumbrance to an operator. In a computer system with a mechanism for detaching or disconnecting a flat panel display from the computer body, the flat panel display is detached in such a case. After that, the flat panel display may erroneously be attached to the computer body while the power supply is turned ON. The attachment of the flat panel display with power supply turned ON may cause malfunctions of the computer system due to rush current. Further, abnormal an voltage may be generated depending on the way of attachment of the flat panel display to the computer body, thus causing a breakdown of the system and flat display panel.